Questions tagged [transactions]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
23 views

Exercise task with main memory

The Exercise is Computer A has a main memory of size HA 2 MiB, and computer B has a main memory of HB = 256 MiB. Both computers process single transactions that have a size of s=84 KiB. Each of the ...
2
votes
0answers
21 views

Distributed transaction problem

Let's suppose there are two banks, Bank A and Bank B. A transaction needs to happen that transfers money from an account in Bank A to an account in Bank B. Bank A and Bank B have separate banking ...
1
vote
1answer
25 views

If a user confirmed a booking or transaction on the database system, but it failed and it falls over to the replica, what if the transaction is lost?

This is an overall system design and DBMS question: If the user books a ticket or an item on a website, how do we solve the issue of confirming a ticket is sold to the user, but the main Database ...
0
votes
0answers
30 views

Lost Update Problem and Recoverability and Commits

Does lost update problem must have Read first? Can Lost-Update problem occur in: 1] Conflict Serializable 2] Strict Recoverable I'm totally confused about basic. R2(X) R1(X) W1(X) C1 W2(X) Does this ...
0
votes
0answers
36 views

How does 2PL protocol apply to schedule of multiple transactions?

If a schedule follows the two-phase locking protocol, does every transaction have to follow 2PL, or is it the case that all locks must appear all unlocks in the whole schedule? I am a little confused ...
1
vote
1answer
116 views

Does upgrading after all locks and before all unlocks violate 2PL?

2PL's rule says: Upgrading of lock (from S(a) to X (a)) is allowed in growing phase. But what if upgrading lies after the last lock and before the first unlock? Does it still count "in the ...